Capacitance Hat's Don't add Audio

[loosecannon]

wow, i was sure high voltage would get his way on this one.
he came here specifically to get this thread closed.
must not want this info at the top of the page.
LC

 

[psycho]

You're the one that said "horizontal waves travel farther" and that's "why we use a cap hat".

So by your definition you believe that putting a cap hat on a vertical antenna (which has vertical polarization) changes the radiated signal into "horizontal waves", which would be horizontal polarization. Apparently you don't understand the difference between polarization and radiation angle. I'm not twisting anything, but you sure are.

And a cap hat changes none of those things you're talking about.

The only things a hat is good for is to keep the sun out of your eyes....unless you wear it ghetto style. They are also good for covering up a bald spot.

 

[76Q]

There's some magic to this cap hat thingy, but I don't have time to get into it

There's some magic to this cap hat thingy, but I don't have time to get into it right now. If I could afford it I'd love to give the Immortal some key time. I use a Monkey made long shaft MM7 with MM capacitance hat and it does wonders on skip. Local groundwave propagation remains the same against 9ft steel whip but with much higher power handling. Don't knock what you don't truly know, physics was part of mother earth, we just put numbers to it to claim it, but its not all ours to have. Bottom line, You can resonate almost anything by modifying components and materials. Antennas look the way they do more out of a tug of war between form and function, but as we discover more the variables which can affect propagation, power and efficiency, antennas will someday, look nothing like they look today. More later...

 

[BOOTY MONSTER]

i think i just got dumber

 

[loosecannon]

There's some magic to this cap hat thingy, but I don't have time to get into it right now. If I could afford it I'd love to give the Immortal some key time. I use a Monkey made long shaft MM7 with MM capacitance hat and it does wonders on skip. Local groundwave propagation remains the same against 9ft steel whip but with much higher power handling. Don't knock what you don't truly know, physics was part of mother earth, we just put numbers to it to claim it, but its not all ours to have. Bottom line, You can resonate almost anything by modifying components and materials. Antennas look the way they do more out of a tug of war between form and function, but as we discover more the variables which can affect propagation, power and efficiency, antennas will someday, look nothing like they look today. More later...

that is one of the stupidest things ive ever read on this forum. :thumbdown:
LC

 

[Shockwave]

I use a Monkey made long shaft MM7 with MM capacitance hat and it does wonders on skip.

An interesting point is being made here concerning the differences between line of sight and sky wave DX propagation. While it is an established fact that a full length linear radiator produces the most field strength on the horizon, I won't be so quick to 100% rule out other possibilities for DX work. Changing polarization and different radiation elevation angles play a significant role in DX. I am reluctant to admit this because I have not done any controlled scientific tests in the area however, I too have seen signs of improved DX performance from some loaded antennas that were still relatively close to 1/4 wavelength physically or from 1/4 waves with larger top hats. The possible advantage only appears in DX and shows slightly less gain on the distant horizon.

It's difficult to determine any small advantages these antennas could have in DX since signals are never stable enough to make a controlled comparison. Instead we are left to make relative generalizations like "I seem to be getting better results with this antenna over another one in DX". I can only theorize why this may be the case. It is my opinion that it has nothing to do with gain since it will be reduced and everything to do with radiation angles. Any horizontal radiation surface including a top hat to some degree, will have entirely different radiation angles then the vertical component since radiation occurs around the conductor. In the case of helically wound coils, they do not produce radiation that is perfectly broadside to their physical orientation. The field can be intense at angles off the ends of the coil. These radiation components may also be reflecting differently off your vehicles groundplane then a straight vertical would.

 

[Marconi]

An interesting point is being made here concerning the differences between line of sight and sky wave DX propagation. While it is an established fact that a full length linear radiator produces the most field strength on the horizon, I won't be so quick to 100% rule out other possibilities for DX work. Changing polarization and different radiation elevation angles play a significant role in DX. I am reluctant to admit this because I have not done any controlled scientific tests in the area however, I too have seen signs of improved DX performance from some loaded antennas that were still relatively close to 1/4 wavelength physically or from 1/4 waves with larger top hats. The possible advantage only appears in DX and shows slightly less gain on the distant horizon.

It's difficult to determine any small advantages these antennas could have in DX since signals are never stable enough to make a controlled comparison. Instead we are left to make relative generalizations like "I seem to be getting better results with this antenna over another one in DX". I can only theorize why this may be the case. It is my opinion that it has nothing to do with gain since it will be reduced and everything to do with radiation angles. Any horizontal radiation surface including a top hat to some degree, will have entirely different radiation angles then the vertical component since radiation occurs around the conductor. In the case of helically wound coils, they do not produce radiation that is perfectly broadside to their physical orientation. The field can be intense at angles off the ends of the coil. These radiation components may also be reflecting differently off your vehicles groundplane then a straight vertical would.

SW, I recently posted a top hat model along with a bunch of other more conventional 1/4 wave ground plane antennas. I note the report below.

In this example of a variety of combinations using 102"/108" whips with suitable ground planes attached, and one model with no ground plane at all, including a top hat model I demonstrated the affects of the top hat using modeling. The Top Hat model did show a small increase in gain at the max angle of 33* degrees, and about the same as all other models @ the lower minor angled lobe at 9* degrees showing a gain of 3.33 dbi over real Earth... as modeled using Eznec5.

This gain and angle information does not provide a clue as to why a top hat antenna with an appreciable sized top hat element would seem to respond better to DX signals vs a radiator without a top hat, but if we look at the max angle pattern for these models we might see the clue as to why...please note the increased compression in the upper lobes area of the top hat model vs the similar area for all the other models listed.

In my real life experience while comparing antennas side by side I can, at times, actually sense this difference with DX responses as well. As I said before, this difference in response is not like a light switch difference, but it is detectable. So, something is going on with shortened radiators with top hats of a modest/large size compared to the wavelength.

View attachment 102 in. Whip a 1_4 Wave Radiator 040611.pdf

 

[Shockwave]

That makes sense seeing it in your models Marconi. I figured it was a change that would only benefit sky wave radiation angles.

 

[loosecannon]

now im not too versed in bent antennas, but what you guys are discussing certainly sounds similar.

an inverted L or a T antenna will raise the current maximum higher and will increase radiation, so can we say that if a top hat gets big enough, it begins to act like a bent antenna?

im just not sure of the matching system required for a T style bent antenna, so its tough to say.


also, with all the BS, hype, and flat out false advertising claims out there, we really shouldnt be guessing about DX signals.
i think we all know how many variables can be involved with those.

i can watch a deadkey from a DX station vary up and down and up and down from 3 to 7 s units, stay steady at 7, then fall right back down to 3 again.
does that mean that his antenna is changing its radiation pattern?
i dont think so.

because of this, when it comes to a particular antenna design's gain on the horizon, we have to go with solid theory based on the laws of our universe.

if EZNEC seems to contradict what Maxwell said, who should we trust?
(im not directing that at anyone, im just illustrating a point)
LC

 

[Marconi]

That makes sense seeing it in your models Marconi. I figured it was a change that would only benefit sky wave radiation angles.

SW, I'm not suggesting that sky wave radiation is to be ignored. This seeming compression thing is just one issue that I was surprised to see, and I heard 55 talk about this factor when I called him to ask for a Merlin to test and I would return it when finised or buy it. I still want to test the Top Hat with a coil underneath.

I believe that we are affected by sky waves in our local contacts much of the time, and sometimes they are good and sometimes they are not. I can't explain it any better, but I think Bob has a sense that determines for him when a contact is or is not affected by shywave propagation.

now im not too versed in bent antennas, but what you guys are discussing certainly sounds similar.

an inverted L or a T antenna will raise the current maximum higher and will increase radiation, so can we say that if a top hat gets big enough, it begins to act like a bent antenna?

im just not sure of the matching system required for a T style bent antenna, so its tough to say.

also, with all the BS, hype, and flat out false advertising claims out there, we really shouldnt be guessing about DX signals. i think we all know how many variables can be involved with those.

i can watch a deadkey from a DX station vary up and down and up and down from 3 to 7 s units, stay steady at 7, then fall right back down to 3 again.
does that mean that his antenna is changing its radiation pattern?
i dont think so.

because of this, when it comes to a particular antenna design's gain on the horizon, we have to go with solid theory based on the laws of our universe.

if EZNEC seems to contradict what Maxwell said, who should we trust?
(im not directing that at anyone, im just illustrating a point)
LC

LC, I think my model Top Hat is about 60% in the vertical radiator. My AstroPlane knock offs and the New Top One are closer to 50%. I just took my Old Top One down with a full 1/4 wave in the top vs. my New Top One, that I've been comparing for several days. The local signals are very similar with an edge for the full 1/4 wave radiator, but I did not notice the distinction in DX or local that I've noticed before, so I'm not sure about my thinking on the subject. I will say some folks claim a Top Hat antenna cannot perform at or near par with a full 1/4 wave radiator, but IMP they are wrong to be so categorical about such a claim.

I did not model any matching in any of my models. I don't know how to model matching devices at this point. Among all the full blown Exnec models I ever seen, none showed a matching device.

I have asked MrSuburban and I think I asked Shockwave and a couple of others for a model with matching included, but thus far no models have been received. I get none to few responses to my questions asked of others regarding modeling in fact.

I have read in places and Henry as intimated to me that method of moments modeling is not based on a particular antenna being matched. So, I assume that matching makes little difference to the end results we are likely to get from the modeling efforts. I can skew a 1/4 wave to have a bad match by physically making the elements show a non-resonant mismatch that is considerable. This is similar to several of my models posted above demonstrating the use of 102"/108" whips and in particular the model with no ground plane at all. I also find in my real experience, within reason, where tuning an antenna has little to really do with the antenna's performance...as best I can tell. I am also doing a real life test model for this idea right now using a 102" whip with no ground plane attached to emulate a heavy mismatch.

Bob has suggested to us many times that tuning the Sigma4/Vector is the secret to best performance at a distance, and in that case if true, I think it has more to do with the collinear affect we suspect is at work in such an antenna. If this ever develops to not be the case, then it goes back to Shockwave's idea about sky wave proprogations...that convinced Bob of what he saw.

I have never really tuned my Sigm4, just constructed it per instructions, and it works fine, in fact it was #1 along with my New Gain Master in my recent testing. So, one day I will have to try and duplicate Bob's ideas. The reason I haven't tried it already, is because he also says the response is less dramatic with the original Avanti Sigma4, because it only has three legs and I also agree that may be true as well. I have prov en several times at my location that I see better results when adding effective radials to my MarconiX antenna.

The big issue with a proper tune is making the TX'r happy in operations, so that it will provide 100% of its energy toward the antenna...and then other factors come into play like the feed line, connectors, inline devices, proper construction, and objects around the antenna may start also ill-affect performance.

As noted in my model of the Top Hat 1/4 wave above it could stand some matching help, because it shows the resistance has gone back down from close to 50 ohms in the conventional model with slanted down radials, to 39 ohms again. This is probably why the Merlin and others like it have the coil added in series to increase the resistive feed point value to a better match.

Just my ideas, not facts.

BTW LC, you mention some laws of the universe. Can you elaborate some more on these laws? Which Maxwell are you telling us objects to something said here, and do you have a direct link to such a subject and a claim that Maxwell made?

 

[Marconi]

Here are several of the more important 1/4 wave antennas with the pattern overlaid and compared.

The legend at the left:
#4 is the antenna with all 108" whip elements that are horizontal- dark blue
#5 has no radials at all - green
#6 is the best antenna modeled using all 102" whip elements - red
#10 is the antenna with a Top Hat - lite blue

View attachment ..25 wave Patternes overlaid and compared..pdf

 

[bob85]

eddie,
its very easy to hear and see when theres multipath on fm, local signals flutter at a time varying rate, they hit a peak then flutter back to where they usually are with a woosh wooosh woooosh sound as the multiple paths arriving at different phase angles sum and cancel each other,

on ssb the effect is similar to the effect you get when switching the polarity of one loudspeaker on a hifi cancelling the bass frequencies but its not switched, it is a variable in and out of phase sound.

 

[Marconi]

eddie,
its very easy to hear and see when theres multipath on fm, local signals flutter at a time varying rate, they hit a peak then flutter back to where they usually are with a woosh wooosh woooosh sound as the multiple paths arriving at different phase angles sum and cancel each other,

on ssb the effect is similar to the effect you get when switching the polarity of one loudspeaker on a hifi cancelling the bass frequencies but its not switched, it is a variable in and out of phase sound.

Thanks Bob, something rings a bell. You probably described that to me before, but sometimes my recall is not up to par. Do you hear something similar on AM or FM? I would think you probably would, right?

 

[76Q]

I just read up on this thread, thanks...

I just read up on this thread, thanks for the continued input plots showing top hats, Marconi. I for one have just compared my originally 80" MM antenna to a modified version that I made and have found no discernable difference in signal in a two mile low power test on TX vs. full length whip. I did the test at 2 miles with 50 ft. elevation rise to target receiver. Furthermore, there is simply no difference in the performance to the places I normally talk, about 50miles groundwave over hilly terrain and the skip that I shoot to the U.S. and the Islands. My top hat replaces about 35" of radiator while the massive 5 wrap center coil replaces about 26" of a full quarterwave radiator. This antenna is impossible to tell apart in performance from my 9 ft whip, and I am attempting to identify ways to alter its vertical pattern response to more favor the use that I require.
Clearly your models show vertical pattern modification by top hat implementation. There are more factors that need to realized, such as at what size of top hat would be optimal to yield the best vertical pattern, interactions with earth by implementation of various height and form hats, etc. Perhaps a model of the Immortal is an important next step as is modeling my own version of it.

76 Biohazard

Here are several of the more important 1/4 wave antennas with the pattern overlaid and compared.

The legend at the left:
#4 is the antenna with all 108" whip elements that are horizontal- dark blue
#5 has no radials at all - green
#6 is the best antenna modeled using all 102" whip elements - red
#10 is the antenna with a Top Hat - lite blue

View attachment 4484

 

[MrSuburban]

I just read up on this thread, thanks for the continued input plots showing top hats, Marconi. I for one have just compared my originally 80" MM antenna to a modified version that I made and have found no discernable difference in signal in a two mile low power test on TX vs. full length whip. I did the test at 2 miles with 50 ft. elevation rise to target receiver. Furthermore, there is simply no difference in the performance to the places I normally talk, about 50miles groundwave over hilly terrain and the skip that I shoot to the U.S. and the Islands. My top hat replaces about 35" of radiator while the massive 5 wrap center coil replaces about 26" of a full quarterwave radiator. This antenna is impossible to tell apart in performance from my 9 ft whip, and I am attempting to identify ways to alter its vertical pattern response to more favor the use that I require.
Clearly your models show vertical pattern modification by top hat implementation. There are more factors that need to realized, such as at what size of top hat would be optimal to yield the best vertical pattern, interactions with earth by implementation of various height and form hats, etc. Perhaps a model of the Immortal is an important next step as is modeling my own version of it.

76 Biohazard

SoCal 76, Fast4Socal76 etc etc etc you sure change your name alot of these forums ...